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		<span class="label">相关内容：</span>
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				<strong>其它背景边框参考</strong>
				<span>选择其它项<!--[if lte IE 7]><ins>IE7 and earlier, Get to die</ins><![endif]--></span>
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		<h1 class="tit">background-position</h1>
		<ul class="info">
			<li><strong>版本：CSS1/3</strong></li>
			<li>2018.3.14</li>
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	<section id="syntax" class="g-mod g-attr">
		<h2 class="tit">语法：</h2>
		<div class="cont">
			<p><strong>background-position</strong>：<a href="#dfn-syntax">&lt;position&gt;</a> <ins class="g-color-css3-new" title="css3">[ , <a href="#dfn-syntax">&lt;position&gt;</a> ]*</ins></p>
			<p id="dfn-syntax"><strong>&lt;position&gt;</strong> = [ left | center | right | top | bottom | <a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a> | <a href="../../values/length/length.htm">&lt;length&gt;</a> ]
|
  [ left | center | right | <a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a> | <a href="../../values/length/length.htm">&lt;length&gt;</a> ]
  [ top | center | bottom | <a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a> | <a href="../../values/length/length.htm">&lt;length&gt;</a> ]
|
  [ center | [ left | right ] [ <a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a> | <a href="../../values/length/length.htm">&lt;length&gt;</a> ]? ] &amp;&amp;
  [ center | [ top | bottom ] [ <a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a> | <a href="../../values/length/length.htm">&lt;length&gt;</a> ]? ]</p>
			<p><strong>默认值</strong>：<mark class="defaultvalue">0% 0%</mark>，效果等同于left top</p>
			<p><strong>适用于</strong>：所有元素</p>
			<p><strong>继承性</strong>：无</p>
			<p><strong>动画性</strong>：是</p>
			<p><strong>计算值</strong>：指定值</p>
			<p><strong>媒　体</strong>：视觉</p>
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		<h2 class="tit">取值：</h2>
		<div class="cont">
			<dl>
				<dt><a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a>：</dt>
				<dd>用百分比指定背景图像在元素中出现的位置。可以为负值。参考容器尺寸减去背景图尺寸进行换算。</dd>
				<dt><a href="../../values/length/length.htm">&lt;length&gt;</a>：</dt>
				<dd>用长度值指定背景图像在元素中出现的位置。可以为负值。</dd>
				<dt>center：</dt>
				<dd>背景图像横向或纵向居中。</dd>
				<dt>left：</dt>
				<dd>背景图像从元素左边开始出现。</dd>
				<dt>right：</dt>
				<dd>背景图像从元素右边开始出现。</dd>
				<dt>top：</dt>
				<dd>背景图像从元素顶部开始出现。</dd>
				<dt>bottom：</dt>
				<dd>背景图像从元素底部开始出现。</dd>
			</dl>
		</div>
	</section>
	<section id="intro" class="g-mod g-attr">
		<h2 class="tit">说明：</h2>
		<div class="cont">
			<strong>指定背景图像在元素中出现的位置。</strong>
			<ul>
				<li>该属性接受<code class="g-code">1~4</code>个参数值。</li>
				<li>
					<p>如果提供三或四个，每个 <a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a> 或 <a href="../../values/length/length.htm">&lt;length&gt;</a> 偏移量之前都必须跟着一个边界关键字（即left | right | top | bottom，不包括center），偏移量相对关键字位置进行偏移。</p>
					<strong>示例：假设要定义背景图像在容器中右下方，并且距离右边和底部各有20px</strong>
					<div class="gquote">
						<p class="gquote-tit"><strong>缩写方式：</strong></p>
						<blockquote class="gquote-cont"><pre><code>background: url(test1.jpg) no-repeat right 20px bottom 20px;</code></pre></blockquote>
					</div>
					<strong>你也可以设置3个参数值：</strong>
					<div class="gquote">
						<p class="gquote-tit"><strong>拆分方式：</strong></p>
						<blockquote class="gquote-cont"><pre><code>background: url(test1.jpg) no-repeat left bottom 10px;</code></pre></blockquote>
						<p class="gquote-info">要注意的是：设置3个或4个值，偏移量前必须有边界关键字。也就是说，形如：<code class="g-value">10px bottom 20px</code>，这样的参数设置是错误的，因为10px前面没有关键字。</p>
					</div>
				</li>
				<li>如果提供两个，第一个用于横坐标，第二个用于纵坐标。</li>
				<li>如果只提供一个，该值将用于横坐标；纵坐标将默认为50%（即center）。</li>
				<li>对应的脚本特性为：<strong>backgroundPosition</strong>。</li>
			</ul>
		</div>
	</section>
	<section id="compatible" class="g-mod g-attr">
		<h2 class="tit">兼容性：</h2>
		<div class="cont">
			<ul class="support-type">
				<li><span class="support">浅绿</span> = 支持</li>
				<li><span class="unsupport">红色</span> = 不支持</li>
				<li><span class="partsupport">粉色</span> = 部分支持</li>
				<li><span class="unknown">灰色</span> = 未知</li>
			</ul>
			<table class="g-data">
				<thead>
					<tr>
						<th>Values</th>
						<th>IE</th>
						<th>Firefox</th>
						<th>Chrome</th>
						<th>Safari</th>
						<th>Opera</th>
						<th>iOS Safari</th>
						<th>Android Browser</th>
						<th>Android Chrome</th>
					</tr>
				</thead>
				<tbody>
					<tr>
						<td><strong>Basic Support</strong></td>
						<td class="support">8.0+</td>
						<td class="support" rowspan="3">40.0+</td>
						<td class="support" rowspan="3">40.0+</td>
						<td class="support" rowspan="3">8.0+</td>
						<td class="support" rowspan="3">40.0+</td>
						<td class="support" rowspan="3">8.0+</td>
						<td class="support" rowspan="3">4.4+</td>
						<td class="support" rowspan="3">28.0+</td>
					</tr>
					<tr>
						<td rowspan="2">3~4个参数<br />Multiple background position</td>
						<td class="unsupport">8.0</td>
					</tr>
					<tr>
						<td class="support">9.0+</td>
					</tr>
				</tbody>
			</table>
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	</section>
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		<h2 class="tit">示例：</h2>
		<div class="cont">
			<textarea cols="90" rows="10">
<!DOCTYPE html>
<html lang="zh-cmn-Hans">
<head>
<meta charset="utf-8" />
<title>background-repeat_CSS参考手册_web前端开发参考手册系列</title>
<meta name="author" content="Joy Du(飘零雾雨), dooyoe@gmail.com, www.doyoe.com" />
<style>
.test {
	border: 1px solid #000;
	width: 400px;
	height: 500px;
	background-image: url(skin/p_103x196_1.jpg);
	background-repeat: no-repeat;
	background-position: center;
}
</style>
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<div class="test">背景图水平垂直居中</div>
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